Are oysters OK on keto diet?

Quick Answer

Oysters are an excellent keto-friendly food. They are very low in carbs and high in nutrients, making them a great addition to a ketogenic diet. Oysters provide high-quality protein, healthy fats, and a variety of vitamins and minerals like zinc, selenium, and B vitamins. Since they are low in carbs and will not knock you out of ketosis, oysters can be enjoyed liberally as part of a well-formulated keto diet.

What is a Keto Diet?

A ketogenic diet, commonly known as keto, is a very low-carb, high-fat diet that shares similarities with low carb diets like the Atkins diet. The main goal of the keto diet is to put and keep your body in a metabolic state called ketosis. To enter ketosis, you restrict your carb intake to around 5% of total calories, typically less than 50 grams of net carbs per day. This forces your body to burn fats rather than carbs for fuel. On a well-formulated keto diet, around 75% of calories come from fat, 20% from protein, and 5% from carbs.

Being in ketosis provides a number of health benefits, including:

  • Enhanced weight loss
  • Improved blood sugar control
  • Reduction in insulin and blood pressure
  • Increased HDL (good) cholesterol
  • Neuroprotective benefits

The keto diet can also help reduce appetite, food cravings, and symptoms of conditions like metabolic syndrome and type 2 diabetes. However, the keto diet requires strict adherence to ultra low carb intake to reap these benefits. Even small amounts of excess carbs can quickly take you out of ketosis.

Keto Diet Guidelines on Carbs

To get into and stay in ketosis, carbs must be restricted to around 5% of total calories or less than 50 grams per day for most people. However, not all carbs count equally on keto. The total carb content includes fiber, sugar alcohols, and net carbs.

Net carbs are calculated by subtracting fiber and sugar alcohols from total carbs. These are the carbs that directly impact ketosis. As such, net carbs are the only ones that need to be restricted on keto, rather than total carbs. Foods like non-starchy vegetables are high in fiber but low in net carbs, so they can be enjoyed freely.

Here are the keto diet guidelines for net carbs:

  • Total Carbs – Fiber – Sugar Alcohols = Net Carbs
  • Aim for less than 50 grams of net carbs per day
  • Limit foods high in net carbs like grains, starchy veggies, fruits, beans, milk, added sugars
  • Prioritize foods low in net carbs like non-starchy veggies, nuts, seeds, high fat dairy, avocados, berries

Carefully tracking net carbs and staying under 50 grams daily is crucial to maintaining ketosis on a ketogenic diet. Even small servings of high carb foods can accumulate quickly and inhibit ketosis.

Are Oysters Keto?

Oysters are one of the best keto diet foods. They are an amazing source of nutrition with minimal impact on net carbs.

Three medium oysters (about 85 grams) contain: (1)

  • Total Carbs: 7 grams
  • Fiber: 0 grams
  • Net Carbs: 7 grams
  • Protein: 6 grams
  • Fat: 2 grams

With just 7 grams of net carbs and 8 grams of high-quality protein per serving, oysters can easily be incorporated into a ketogenic diet. They make a great addition to keto staples like salmon, avocado, and leafy greens.

Unlike high carb bivalves like clams, mussels, and scallops, the carb content of oysters is low enough to remain in ketosis while enjoying their stellar nutritional benefits.

Benefits of Oysters on Keto

Here are some of the key benefits of adding oysters to a well-formulated ketogenic diet:

Excellent Source of Zinc

Oysters stand out as one of the best food sources of the essential mineral zinc. Just 3 oysters provide over 90% of the RDI for zinc. (2)

Zinc plays a vital role in immune health, DNA and protein synthesis, wound healing, thyroid function, blood sugar control, and over 100 enzymatic reactions in the body. (3)

Many people following a keto diet are deficient in zinc. (4) Oysters can help offset this due to their amazing zinc content.

Rich in Selenium and B Vitamins

In addition to zinc, oysters are loaded with other key micronutrients:

  • Selenium – Powerful antioxidant that supports thyroid function and immune health
  • Vitamin B12 – Essential for nerve tissue, DNA synthesis, and energy levels
  • Vitamin B3 – Supports brain health and energy production

These nutrients are crucial on keto to counter potential deficiencies. Oysters provide them in ample amounts.

High Quality Complete Protein

With 6 grams of protein in just 3 oysters, they provide an excellent source of complete, amino acid balanced protein on keto.

Protein is especially important on a ketogenic diet. It helps maintain muscle mass as the body burns fat for fuel in ketosis.

The abundant protein content allows oysters to promote muscle growth and prevent loss of lean body mass when restricting carbs.

Source of Omega-3 Fatty Acids

Oysters contain omega-3 fatty acids EPA and DHA, though in smaller amounts than fatty fish like salmon. (5)

These anti-inflammatory fats support heart health, brain function, and development. Ketogenic diets can be low in omega-3 fats, so oysters help provide a boost.

High in Bone-Building Minerals

Oysters are packed with minerals that play a key role in bone health, including:

  • Zinc – Deficiency linked to bone loss
  • Calcium – Essential for bone matrix formation
  • Selenium – Antioxidant that protects bone cells
  • Magnesium – Promotes calcium and vitamin D absorption

These bone-supporting minerals can counter potential deficiencies and skeletal changes on a long-term keto diet. (6)

Potential Concerns

While oysters are undoubtedly keto-friendly, there are some potential drawbacks to keep in mind:

High Sodium Content

Like most shellfish, oysters are high in sodium. Three oysters contain about 100 mg of sodium, which is 5% of the recommended daily limit. (7)

Those with high blood pressure or on a sodium-restricted diet may want to limit oyster intake to avoid excess sodium. However, most people on keto who are otherwise healthy can safely consume them.

Risk of Contamination

As filter feeders, oysters can concentrate bacteria and parasites from polluted waters. Contaminated oysters put you at risk for serious foodborne illnesses.

Only source oysters from reputable suppliers and cook thoroughly to minimize the risk of infection. People with compromised immune systems should avoid raw oysters.

Potential Allergies

Some people are allergic to oysters and need to avoid them entirely. Allergic reactions can range from mild nausea and itching to severe anaphylaxis.

If you have a shellfish allergy, it is best not to add oysters to your keto diet due to the potential safety risks.

How to Add Oysters to Your Keto Diet

Here are some simple ways to start enjoying the benefits of oysters on a ketogenic diet:

Oyster Fritters

Dip oysters in beaten eggs, coat with pork rinds and almond flour, then pan fry until crispy for a delicious low carb fritter. Enjoy dipped in keto tartar sauce.

Smoked Oyster Lettuce Wraps

Fill butter lettuce leaves with smoked oysters and keto-friendly dippings like avocado, hot sauce, or tartar sauce for a fast, high protein lunch.

Oyster and Avocado Salad

Top a bed of leafy greens with fresh oysters, avocado slices, red onion, olive oil, and apple cider vinegar for an easy keto salad.

Oyster Chowder

Make a creamy keto oyster stew by cooking oysters in bone broth with your choice of sautéed veggies like celery, leeks, and low carb thickeners like xanthan gum.

Oysters Rockefeller

Top broiled oysters with sautéed spinach, parsley, butter, lemon zest, bacon, and Parmesan cheese for a restaurant favorite at home.

Oyster Stir Fry

Cook oysters briefly with keto veggie staples like zucchini noodles, bok choy, and mushrooms flavored with sesame oil, garlic, and ginger.

Keto Oyster Recipes

Here are some delicious keto recipes featuring oysters:

Keto Oyster Po’ Boy

  • Sauté fresh oysters with Cajun seasoning
  • Serve on keto bread or lettuce wraps
  • Top with lettuce, tomato, avocado, and tartar sauce

Keto Bacon and Oyster Stuffing

  • Sauté oysters, bacon, onions, celery in butter
  • Fold in chopped kale, herbs, and pork rinds
  • Bake until crispy and top with Parmesan

Keto Oyster Casserole

  • Sauté oysters with garlic, cream, and Parmesan
  • Layer shredded zucchini, oysters, bacon, and cheese
  • Bake until bubbly and top with avocado


Oysters are a smart addition to the keto diet. A few key takeaways:

  • Extremely low in net carbs – Won’t interfere with ketosis
  • Excellent source of zinc, selenium, B vitamins
  • Provide high-quality complete protein
  • Supply omega-3 fats EPA and DHA
  • Loaded with bone-healthy minerals
  • Potential risks come from sodium content, contamination, allergies
  • Can be enjoyed cooked in many recipes or raw

Overall, oysters are a keto superfood. They deliver a powerhouse of nutrition to support health on a ketogenic diet. Include them regularly along with other keto staples for an easy nutritional boost.

Frequently Asked Questions

Are oysters high in carbs?

No, oysters are very low in net digestible carbs. A 3-ounce serving of oysters contains about 7 grams of total carbs but no fiber. So the net carb count is only 7 grams, which fits easily into a 50-gram daily limit on keto.

Can you eat raw oysters on keto?

Yes, raw oysters are totally keto-approved. Their stellar nutrition and minerals are not diminished by cooking. However, eating raw oysters does increase the risk of bacterial infection. Make sure raw oysters are from a reputable source. Those with compromised immune systems should cook oysters thoroughly before eating.

Are oysters healthier than clams and mussels?

Overall, oysters are healthier than clams and mussels in the context of a keto diet. Oysters are significantly lower in carbs and higher in essential nutrients like zinc. Clams and mussels are higher in carbs so need to be limited carefully on keto. Oysters provide greater nutritional benefits per gram of net carbs.

Can you eat fried oysters on keto?

Fried oysters coated in flour or breadcrumbs are not keto-friendly due to the high carb content of the coatings. However, oysters can be fried in a keto way. Try coating oysters in beaten eggs, pork rind crumbs, and almond flour before frying to keep the carb count low. Similarly, oysters fried in high oleic sunflower oil are also a great option.

Do oysters raise cholesterol?

Oysters are high in cholesterol, containing 40-50 milligrams per medium oyster. However, dietary cholesterol has a minimal effect on blood cholesterol for most people. Saturated fat intake plays a bigger role. For otherwise healthy individuals, moderate oyster consumption as part of a keto diet is unlikely to adversely impact cholesterol levels.

The Bottom Line

Oysters are a phenomenal addition to the ketogenic diet. With their stellar nutrition profile, abundance of essential minerals, and minimal net carb impact, oysters can and should be enjoyed regularly to enhance the benefits of keto. Use their versatility to add oysters to your favorite keto recipes for added nutrition and variety. Oysters provide a powerhouse nutrition boost without disrupting ketosis.

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